METHOD FOR PREVENTING GENERATION OF INTERFERENCE PATTERN GENERATED ON ROLL TO BE ENGRAVED

PURPOSE:To allow the execution of high-quality engraving without generating interference patterns and to prevent the generation of the interference patterns to be generated on a roll to be engraved in the method for engraving the roll to be engraved by a laser exposing method. CONSTITUTION:An aq. soln. consisting of polyvinyl alcohol(PVA) as a required high- ratio component and silicon dioxide as a required slight-ratio component is applied by overlap coating on a photosensitive film as a protective film for preventing the oxidation at the time of reaction of the photosensitive film with a laser beam. This aq. soln. turns into a colloidal soln. in which the PVA is completely dissolved and the microparticles of the silicon dioxide are uniformly dispersed in the lump state aggregated several pieces to several tens pieces thereof. Then, the lumped particles aggregated with several pieces to several tens pieces of the microparticles of the silicon dioxide are eventually dispersed uniformly into the protective film for preventing oxidation applied by overlap coating on the photosensitive film. Adequate irregular reflections can be applied to the incident light and reflected light of the laser beam within the protective film, by which the generation of the interference pattern to be generated on the roll to be engraved is prevented and the engraving without generating the interference patterns is executed.